in this can you explain +1?

def remove_middle(lst, start, end):
return lst[:start] + lst[end+1:]

#Uncomment the line below when your function is done
print(remove_middle([4, 8, 15, 16, 23, 42], 1, 3))

If you mean end+1. That is a design choice that the end index that you want to exclude is inclusive. This is the opposite of range, for example which has the end of the range excluded.

So the end+1 gets you all items in the array after the end index specified, meaning the end index is included in the removed section.

That code should really check that the end+1 (well, technically start too) won’t go outside the range of the list.